Device for detecting a rotational angle of a rotatable part

Abstract

A device for detecting a rotational angle of a rotatable part, e.g., a steering wheel, includes at least one magnet, at least one sensor which detects the magnetic field of the magnet, at least one housing in which the sensor and/or the magnet is/are movably situated relative to one another, and at least one printed circuit board which is contacted in an electrically conductive manner by at least one connecting element of the sensor. The printed circuit board has at least one interface or a connector plug from which the output signal of the sensor or an output signal derived therefrom is relayed to an evaluation unit which ascertains the absolute position of the rotational angle as a function of the output signal.

What is claimed is: 
     
       1. A device for detecting a rotational angle of one of a steering wheel or a steering column of a vehicle, comprising:
 at least one magnet; 
 at least one first sensor configured to detect the magnetic field of the magnet, and wherein the magnet and the first sensor are movably situated relative to one another; 
 at least one housing, wherein at least one of the magnet and the first sensor is situated in the housing; 
 at least one printed circuit board contacted in an electrically conductive manner by at least one connecting element of the first sensor, the printed circuit board having one of an interface or a connector plug; 
 an evaluation unit situated at a distance from the housing, wherein one of an output signal of the first sensor or a signal derived from the output signal of the first sensor is relayed from the one of the interface or the connector plug of the printed circuit board to the evaluation unit, and wherein the evaluation unit is configured to ascertain the absolute position of the rotational angle of the one of the steering wheel or the steering column as a function of the output signal of the first sensor; and 
 a second sensor configured to detect the magnetic field of the magnet, the second sensor being situated at a distance from the first sensor and outputting an output signal phase-shifted with respect to the output signal of the first sensor, wherein the at least one printed circuit board includes at least one linkage unit which gates the two output signals of the first and second sensors to form a gated output signal. 
 
     
     
       2. The device as recited in  claim 1 , wherein the printed circuit board includes a signal-level-shifting device configured to shift the signal level of at least one output signal of at least one of the first sensor and the second sensor. 
     
     
       3. The device as recited in  claim 2 , wherein the signal-level-shifting device shifts the signal level of at least one output signal of at least one of the first sensor and the second sensor to a potential which differs from one of supply potential or ground potential of the at least one of the first sensor and the second sensor. 
     
     
       4. The device as recited in  claim 2 , further comprising:
 a third sensor providing an output signal having a signal level differing from signal levels of the output signals of the first and second sensors. 
 
     
     
       5. The device as recited in  claim 2 , wherein the gated output signal has a higher resolution. 
     
     
       6. The device as recited in  claim 2 , wherein the evaluation unit includes an error recognition unit configured to recognize whether an error is present in at least one of the first and second sensors on the basis of the signal level of at least one of the output signals of the first and second sensors. 
     
     
       7. The device as recited in  claim 2 , wherein at least one connecting element of at least one of the first and second sensors has at least one bending region for compensating for voltages resulting from thermal stress. 
     
     
       8. The device as recited in  claim 7 , wherein the at least one connecting element of the at least one of the first and second sensors has at least one further bending region for guiding the at least one connecting element to the printed circuit board for electrical contacting. 
     
     
       9. The device as recited in  claim 8 , further comprising:
 at least one retaining element provided for the sensor. 
 
     
     
       10. The device as recited in  claim 9 , wherein the at least one retaining element is configured in the form of ribs one of (i) on the housing or (ii) on a part connected to the housing. 
     
     
       11. The device as recited in  claim 7 , wherein at least one pocket is provided in the housing for accommodating at least one of the first and second sensors. 
     
     
       12. The device as recited in  claim 7 , wherein at least one of the first and second sensors is situated to sense the at least one magnet's magnetic field extending essentially parallel to the rotational axis of one of the steering wheel or the steering column. 
     
     
       13. The device as recited in  claim 7 , wherein at least one fastening arrangement is provided in the housing for connecting the printed circuit board to the housing. 
     
     
       14. The device as recited in  claim 13 , wherein the fastening arrangement is thermally deformable for fastening the housing to the printed circuit board. 
     
     
       15. The device as recited in  claim 13 , wherein the fastening arrangement is configured as at least one rivet connection. 
     
     
       16. The device as recited in  claim 1 , further comprising a hub integrated with the magnet in the housing. 
     
     
       17. A device for detecting a relative rotational angle of one of a steering wheel or a steering column of a vehicle, comprising:
 at least one magnet; 
 at least one first sensor configured to detect the magnetic field of the magnet, and wherein the magnet and the first sensor are movably situated relative to one another, the first sensor detecting a relative rotational angle of the steering column; 
 at least one housing, wherein at least one of the magnet and the first sensor is situated in the housing; 
 at least one printed circuit board contacted in an electrically conductive manner by at least one connecting element of the first sensor, the printed circuit board having one of an interface or a connector plug; 
 an evaluation unit situated at a distance from the housing, wherein one of an output signal of the first sensor or a signal derived from the output signal of the first sensor is relayed from the one of the interface or the connector plug of the printed circuit board to the evaluation unit, and wherein the evaluation unit is configured to ascertain the absolute position of the rotational angle of the one of the steering wheel or the steering column as a function of the output signal of the first sensor; and 
 a second sensor configured to detect the magnetic field of the magnet, the second sensor being situated at a distance from the first sensor and outputting an output signal phase-shifted with respect to the output signal of the first sensor, wherein the at least one printed circuit board includes at least one linkage unit which gates the two output signals of the first and second sensors to form a gated output signal.